The eyelids develop from the frontonasal and maxillary processes during embryogenesis. They contain skin, muscle, fibrous tissue and glands that work together to protect the eye. The orbicularis oculi muscle helps with blinking while the levator palpebrae superioris muscle elevates the upper eyelid. The tarsal plates provide structure and the meibomian glands secrete oils to form the tear film. Blood vessels from the internal and external carotid arteries provide a rich blood supply to support the eyelids' functions.

1. ANATOMY OF THE
EYELIDS
DR ARPITA

2. • Eyelids acts as shutters protecting the eye
from injuries and excessive light
• Help in spreading tear film over cornea and
conjunctiva via blinking and also helps
eliminate tears from lacrimal lake
• Contribute to facial features of the individual
• Relay information regarding the state of
wakefulness and attention of the person

3. EMBRYOLOGY
• Development of the five pharyngeal arches
occurs in the first few weeks of gestation
Mesenchymal proliferation occurs cephalad to
the first brachial arch to form the facial
processes: the frontonasal, medial nasal, lateral
nasal,maxillary and mandibular
• The upper eyelids are formed from the
frontonasal process
• The lower eyelids are formed from the maxillary
process

5. • The appearance of the eyelid fold marks the
beginning of eyelid development during the
sixth or seventh week of gestation.
Incomplete eyelid fold development is
thought to be the cause for a number of
congenital eyelid anomalies, including
ablepharon, cryptophthalmos, and
microblepharon

6. • A. Eyelid fusion—8 to 10 weeks gestation.
• colobomas of the eyelid margin
B. Development of eyelid structures—3 to 4
months gestation.
congenital ptosis
C. Eyelid dysjunction—5 to 6 months gestation
ankyloblepharon, blepharophimosis,
epicanthus, and euryblepharon.

8. GROSS ANATOMY
• 1)EXTENT AND POSITION OF EYELIDS –
• Upper eyelid extends from eyebrow to
superior boundary of palpebral fissure
• Lower eyelids – inferior boundary of
palpebral fissure to merge into cheeks
• In primary postion upper lid covers one sixth
of cornea and lower lid just touches cornea

9. 2)LID CREASES
AND FOLDS
• Superior lid crease –
attachment of LPS aponeurosis
to skin
• Inferior lid crease – Fibrous slips
from fascia surrounding inferior
rectus muscle which attach to
skin
• Lid folds – loose skin and
subcutaneous tissue over the
crease
• Lower lid has nasojugal and
malar creases which are
junction b/w skin of lids and
denser tissue of cheek
• Limit spread of blood/fluid
downwards from lids to cheek

10. • Superior lid crease is usually 8-12mm above the
upper lid margin in Europeans .
• It is lower in Asians being around 2-5mm above
upper lid margin – since the orbital septum and
aponeurosis fuse at a lower level
• This allows preaponeurotic fat to occupy a postion
more inferior and anterior creating the appearance
of a fuller eyelid fold

11. 3)CANTHI
Two eyelids meet at the inner and outer canthi
Lateral canthus is in contact with eyeball
Medial canthus is separated from globe by the tear lake
In this area there is caruncle and plica semilunaris
CARUNCLE- Modified skin containing sebaceous glands
and hairs
PLICA SEMILUNARIS- Highly vascular crescent shaped
fold of conjunctiva .Vestigial structure analogous to
nictitating membrane of animals

12. • 4) EYELID MARGINS – 2mm in width
• Each lid margin divided into 2 parts by
lacrimal papilla – Lacrimal portion medially –
devoid of lashes/glands and Ciliary portion
laterally
• Approximately 100 to 150 cilia -upper eyelid,
and 50 to 75 cilia -lower eyelid., arranged in
two to three rows
Glands of Zeis and Moll open into each hair
follicle
Dense plexus of nerves and vesssels around
follicle – exquisite tactile sensibility

13. Both meibomian glands and eyelashes
differentiate during the second month of
gestation from a common pilosebaceous unit.
• Congenital distichiasis.
• Acquired distichiasis

14. . The gray line is also referred to as the muscle
of Riolan and represents the pretarsal
orbicularis muscle on the eyelid margin.
An incision posterior to the gray line along
the eyelid margin demarcates the anterior
lamella from the posterior lamella of the
eyelid

15. • 6)PALPEBRAL FISSURE
• Space between upper and lower lid margins
• At birth around 20 mm width and 8 mm
height
• In adults around 30 mm width and 10 mm ht
• In 50% people lateral canthus in about 2mm
higher than medial – greater than this
produces a mongoloid slant
• Lateral canthus placed lower than medial –
antimongoloid slant

16. STRUCTURE OF EYELID
SKIN
SUBCUTANEOUS TISSUE
STRIATED MUSCLES
SUBMUSCULAR CONNECTIVE TISSUE
FIBROUS LAYER
NON STRIATED MUSCLE
CONJUNCTIVA

17. SKIN
Thinnest in the body contributing to ease of
mobility of lids
Constant movement with each blink – laxity
increases with age. This is called
dermatochalasis
SUBCUTANEOUS TISSUE
• Loose areolar connective tissue containing
No Fat – thus readily distended by oedema or
blood

18. STRIATED MUSCLE
• 1) Orbicularis oculi – Main protractor of
eyelid
• Innervated by cranial nerve 7
• Divided into three parts:
• Pretarsal Involuntary eyelid movmts
• Preseptal
• Orbital Forced eyelid closure

20. Pretarsal part-
Superficial origin-MCT
Deep origin – post lacrimal crest
Deep heads fuse near common
canaliculus to form Horners
muscle (Pars lacrimalis)
Contraction of which draws the
eyelids medially and
posteriorly. The resulting lateral
pull creates a negative pressure
in the lacrimal sac and draws
the tears from the canaliculi
into the sac.
Laterally attaches at lateral
canthal tendon

21. • Preseptal part arises from MCT medially and
forms Lateral palpebral raphae laterally
• Orbital portion arises from MCT , frontal
bone , maxillary bone – fibres form a ellipse
and insert below origin
• Near eyelid margin fibres of pretarsal part –
Muscle of Riolan (pars ciliaris) – creates gray
line , plays a role in meibomian glandular
discharge , blinking and position of eyelashes

23. • 2)LPS – Originates in the apex of orbit from
sphenoid bone
• Courses forward as Muscular portion for
around 40mm then descends vertically and
fans out as an aponeurosis around 15mm
long
• Whitnall ligament is located at transition
zone – acts as a fulcrum for levator
transferring its vector from ant-post to sup –
inf direction
• Its analogue in lower lid is Lockwood
ligament

24. • Whitnalls ligament is an important surgical
landmark – easy to see intraoperatively as a
strong white band of fibrous tissue
• Generally tissue superior to ligament is
muscle while inferior is aponeurosis

25. • Lateral horn of levator aponeurosis divides
lacrimal gland into orbital and palpebral
lobes , attaches to LCT
• Medial horn attached to MCT and post
lacrimal crest
• Lower down it divides into - anterior portion
which inserts onto skin &
• Posterior portion - inserts onto lower half of
tarsus
• Disinsertion , dehiscence of aponeurosis
following trauma/Sx/senescence may give
rise to PTOSIS

26. • Capsulopalpebral fascia
in lower lid arises from
inf rectus ms , encircles
inf oblique ms .
• Its two heads join to
form Lockwood
ligament
• Fuses with orbital
septum and inserts
onto inf tarsal border
• Inf tarsal muscle
analogous to Muller ms

27. SUBMUSCULAR CONNECTIVE TISSUE
• Nerves and vessels of lid lie in this layer , so
to anaesthetise the lid injection is made in
this plane
• Splits the lid into anterior and posterior
lamella
• In upper lid communicates with
subaponeurotic stratum of scalp – dangerous
area of scalp

28. FIBROUS LAYER
• 1)Tarsal plate - Dense fibrous tissue that forms
the skeleton of eyelids giving them shape and
firmness
• 30mm long , 1mm thick , upper tarsus 10mm in
ht , lower tarsus 5mm in ht
• Tarsal plates have rigid attachments to
periosteum via canthal tendons
• The upper tarsus contains approximately 30
meibomian glands, and the lower tarsus
contains approximately 20. The oil-secreting
glands are aligned vertically

29. • 2) Septum orbitale – arises from periosteum
over superior and inferior orbital rims
• Fuses with levator aponeurosis in upper
eyelid and capsulopalpebral fascia in lower
eyelid
• Separates the eyelids from the orbit and
serves as an important anatomic barrier to
infection, hemorrhage, and edema.
• Fat seen in an eyelid laceration means that
septum has been cut and and that deeper
tissues including eye and brain may be
injured

31. • Orbital or preaponeurotic fat is an important
surgical landmark as it lies right behind orbital
septum and in front of levator aponeurosis

32. MEDIAL CANTHAL TENDON
• Can be divided into two parts –
• Anterior part – arises from ant lacrimal crest
• Angular artery and vein passes over medial
part of ligament , artery being medial to
veins
• Splits into upper and lower bands at medial
canthus , these contain lacrimal canaliculi
,enclose the caruncle , delimit and give shape
to medial canthus

33. • Posterior part passes behind lacrimal sac
from ant lacrimal crest to post lacrimal crest

34. • Fractures at medial canthus cause the medial
canthus to be displaced laterally
Telecanthus
• Medial canthal tendon is at about the same
position as the Cribriform plate .In any
operation involving the
removing/repositioning of bone superior to
MCT , there is risk of inadvertent CSF leak

35. LATERAL CANTHAL TENDON
• Laterally attached to Whitnalls tubercle and
medially to ends of upper and lower tarsal
plates
• Laxity of lower eyelid is major cause of
ectropion – occurs due to lengthening of
lateral canthal tendon with age
• Lateral canthotomy is a sight saving
procedure to relieve orbital pressure due to
retrobulbar hemorrhage

37. NON STRIATED MUSCLES
• Mullers muscle originates on undersurface of
L.aponeurosis , inserts along upper eyelid
superior tarsal margin
• Sympathetically innervated smooth muscle
• Provides approx 2mm elevation to upper lid
• If interrupted – eg HORNERS SYNDROME – mild
ptosis ensues
• Peripheral arterial arcade is found b/w Lps
aponeurosis and Mullers ms - this vascular
arcade serves as a surgical landmark to identify
Mullers muscle

38. Muller's muscle: A 10-mm
strip of Muller's muscle is
preserved in this cadaver
demonstrating its origin
from the underside of the
reflected levator muscle
(thick arrow) and its
insertion onto the superior
ridge of the tarsus.

39. CONJUNCTIVA
• Posterior most layer
of eyelid
• Consists of non
keratinising
squamous
epithelium
• Contains openings of
glands of Krause and
Wolfring

40. ARTERIAL SUPPLY
• A network of vessels derived from two major
sources, the internal and the external carotid
arteries, richly vascularizes the eyelids
• Collateralization between the internal and external
systems contributes to the rapid wound healing and
the low incidence of infection following eyelid
surgery.
• As the vessels approach the eyelids, branches of the
ophthalmic artery from the internal carotid artery
and branches of the facial arteries off of the
maxillary branch of the external carotid artery form
the marginal and peripheral vascular arcades of the
eyelids

42. VENOUS DRAINAGE
• Divided into pretarsal and postarsal
• Pretarsal drains into angular vein medially
and superficial temporal vein laterally
jugular veins
• Postarsal drainage is into orbital veins
cavernous sinus

43. LYMPHATIC DRAINAGE
• Lymphatic vessels serving medial side of
eyelid drain submandibular lymph nodes
• Those serving lateral portions of eyelids drain
into preauricular deep cervical

44. NERVES
• Motor nerves – facial nerve (orbicularis)
• oculomotor nerve (LPS)
• Sensory nerves – derived from V1 and V2
• Supraorbital , supratrochlear , infratrochlear
,lacrimal ,infraorbital ,infratrochlear
• Sympathetic nerves – Mullers muscle

45. THANK YOU